While the U.S. does not want to be the policemen of the world, the U.S. has to "do something" to address burgeoning North Korea's nuclear provocations, including "being prepared for military operations if necessary," National Security Adviser H.R. McMaster said Sunday.

"It's an open defiance of the international community," retired Gen. McMaster told "Fox News Sunday" about North Korea's nuclear aspirations and emboldened missile testing. "North Korea poses a grave threat to the United States, our great allies in the region – South Korea and Japan in particular, but also to China and others.

"It's important for all of us to confront this regime. . . . None of us can accept a North Korea with a nuclear weapon."

President Trump has "made it clear he is going to resolve this issue one way or the other," McMaster said, but the preference is to "resolve this issue short of military action."

"What this president has done, he has now connected what our military options are with what we are trying to do politically," McMaster told host Chris Wallace. "For too long, those two things were disconnected from each other, so you need the viable option, the military option, to help make what your doing diplomatically, economically with sanctions, viable – to be able to resolve this problem short of what would be, as the president said, a major, major war and a humanitarian catastrophe."

A period of strategic patience with North Korea is coming to end, though, Wallace intimated to McMaster.

"Well, yes, we do have to do something, and so we have to do something, again, with partners in the region and globally, and that involves enforcement of the U.N. sanctions that are in place," McMaster told Wallace. "It may mean ratcheting up those sanctions even further, and it also means being prepared for military operations if necessary."

McMaster praised President Trump's master stroke of reaching out to China President Xi Jinping to assist with North Korea.

"The president, I think, has been masterful in terms his development of a relationship with President Xi and the discussions that led them to understand this is the place where the United States and the Chinese understand their interests overlap.

While the U.S. does not want to be the policemen of the world, the U.S. has to "do something" to address burgeoning North Korea's nuclear provocations, including "being prepared for military operations if necessary," National Security Adviser H.R. McMaster said Sunday."It's...